Thermo-Magnetic Motor



(N0 Made BEST AVAILABLE COP N. TESLA.

THERMO MAGNETIC MOTOR.

No. 396,121. Patented Jan.15,1889.

2 Sheets-Sheet 1.

BEST AvAxLABLE GOP (NoModeL) 2 SheetsSheet 2.

N. TESLA.

THERMO MAGNETIC MOTOR.

No. 396,121 Patented Jan. 15, 1889.

' stored to move the body heat against a body that BEST AvAiLAsLE cc?UNITED STATES.-

PATENT OFFICE.

NIKOLA 'rEsLA, or SMILJAN, LIKA, AUSTRIA-HUNGARY.

THERMO-MAGNETIC MOTOR.

. SPECIFICATION forming part-of Letters retentive. 396,121, datedJanuary 1-5, 1889. Application filed March so, 1886. Serial no. 197,115;(No model.)

To all whom it may concern.-

Be it known that I, NIKOLA 'IESLA, of. Smiljan, Lika, Border Country ofAustria-Hungary, have invented an Improvement in ThermoMagnetic Motors,of which the following is a specification.

It is well known that heat applied to a magnetized body will lessen themagnetism, and if the temperature is raised sufficientl y the magnetismwill be neutralized or destroyed.

In my present invention I obtain mechanical power by a reciprocatingaction resulting from the joint operations of heat, magnetism, and aspring or weight or other foreethat is to say, I subject a bodymagnetized by induction or otherwise tot-he action of heat until themagnetism is sufiiciently neutralized to allow a weight or spring togive motion to the body and lessen the action of the heat, so vthat themagnetism may be sufiiciently rein the opposite direction, and againsubject the same to thedemagnetizing of the heat.

In carrying out my invention I am able to make use of either anelectro-magnet ora permanent magnet, and I preferably direct theismagnetized by in duction, rather than directly against a perma nentnngnet, thereby avoiding the loss of magnetism that might result in thepermanent magnet by the action of heat. I also provide for lessening theVolume of the heat or for intercepting the same during that portion ofthe reciprocation in which the cooling action takes place.

In the drawings I have rcpresentml by diagrams some of the numerousarrangements that may be made use of in carrying out my invention. Inall of these figures the magnctspoles are marked N S, the armatnre A,the ,Bnnsen burner or other source of heat II, the axisot' motion M, andthe springer the equivalent theroofnamely, a weightis marked W.

In Figure 1 the permanent magnet N is eonnected with a frame, F,supporting the axis M, from which the arm-P h. ngs, and at the lower endof which the armature A is supported. The stops 2 and 3 limit the extentof motion, and the spring \V tends to draw the armatureA away from themagnet N. It is now to be understood that the magnetism wheel shaftattraction of the magnet N overcomes the spring \V and draws thearmature A back again above theliinrner lI, so that thesalne is againheated and v the, operations are repeated. The reciprocating mvementsthus obtained are employed as a source of mechanical power in anydesired manner. Usually a eonnectingrod: to a crank upon a flyin Fig.10; but I do not respect. a

Fig. 2 represents the same parts as before described; but anelectro-magnet is illustrated in place of a permanent magnet. Theoperations, however, are the same.

In Fig. 3 I have shown the same parts as in Figs. '1 and 2, only theyare differently arranged. The armature A, instead of swinging, isstationary and held by an arm, I", and the core N S of theelectro-magnet is made to swing within the helix. Q, the said eore beingsuspended by the arm P from the pivot M. A shield, R, is connected withthe magnet-core and swings therewith, so that-after the heat hasdemagnetized the arimtture A to such an extent that the spring Vi drawsthe core N S away from thearmature A the shield R comes between theflame ll and armature A, thereby intercepting the action of the'heat andallowing the armature to cool, so that the limit myself in thismagnetism, again preponderating, causes the movement of the core N Stoward the armature A and the removal of the shield R from above theflame, so that the heat again acts to lesson or neutralize themagnetism. A rotary or other movement may be obtained from thisreciprocation. Fig. 4 corresponds in every respect with Fig. 3, exceptthat a permanent horseshoemagnet, N S, is represented as taking theplace of the eleetro-magnet in said Fig. 3.

In Fig. 5 I have shown a helix, Q, with an armature adapted to swingtoward or from will be .made use of, as indicated the helix. In thiscase there may be a softiron core in the helix, or the armature mayassume the form of a solenoid-core, there being nopermauent core withinthe helix.

= Fig. 6 is an endview, and Fig. 7 a plan view, illustrating myimprovmnent as applied to a swinging arinaturc,1\, and a stationarypermanent magnet, N h. in this instance I apply the heat to an auxiliaryarmature or keeper, '1, which is adjaeentioand preferably in directcontact with the magnet. This armature '1, in the form oi? a plate ofsheetiron, extends across from one pole to the other I and is ofsufficient sectionjopractically form a keeper for the magnet, so thatwhen this armature '1 is cool nearly allthe lines of force pass over thesame and ver little free magnetism is exhibited. Then the armature A,which swings freely on the pivots M in front of the poles N h, is verylittle attracted and the spring s pulls the same away from the polesinto the position ii'ulicated in the drawings. The heat is di reetedupon the i ron plate 'I at some distance from the magnet, so

as to allow the magnet to he kept (5()lll]')1tIlt-.

tively cool. 'lhis heat is applied beneath the plate by means of theburners H, and there is a connection from the armatureA or itspivot tothe gas-cock 6 or other device for regulating the heat. The heat actingupon the m ido' dle portion of the plate '1, the magnetic conduetivityof the heated portion is diminished or destroyed, anda great number ofthe lines of force.v are deflected over, the ,armature A,

which is now powerfully attracted and drawn into line, ornearly so, withthe poles N S. In so doing the cock 6 is nearly closed and the plate '1cools, the lines of force are again defleeted over the same, theattraction exerted upon the armature A is diminished, and the spring Wpulls the same away from the magnet into the position shown by fulllines, and the operations are repeated. The arrangement shown in l ig. 6has the advantages that the magnet and armature are kept cool and thestrength of the permanent magnet'is better preserved, as the magneticcircuit is constantly closed.

In the plan view, Fig. 8, I have shown a permanent magnet andkeeper-plate, 'l, similar to those in. Figs. 6 and 7, with the burners Hfor the gas beneath the same; but the I 39 BEST AVAlLABLE CO1 armatureis pivoted at one end to one pole of the magnet and the other end swingstoward and from the other pole of the magnet. The apring W acts againsta lever-arm that projeets from the armature, and the supply of heat hasto be partly cut off by a connection to the swinging armature, so as tolessen the heat acting upon the keeper-plate when the armature A hasbeen attracted.

Fig. 9 is similar in Fig. 8, except that the keep(.*r"l is not made useof and the armature itself swings into and out of the range of theintense action of the heat from the burner li.

Fig. 10 is a diagram similar to Fig. .1, except that in place of using aspring and stops the armature is shown as connected byalink, 12, to thecrank 13 of a fly-wheel, so that the flywheel will be revolved asrapidly as the armature can be heated and cooled to the necessaryextent. A spring may be used in addition, as in Fig. l.

'In Fig. '1 ly the twoarmaturcs A A are eounect'ed by a link, so thatone will be heating while the other is cooling, and the attractionexerted to move the cooled armature is availed of to draw away theheated armature instead of using a spring.

I have shown in the drawings several ways of carrying out my invention;but said invention is not limited by any particular form, arrangement,or construction of devices.

I claim as my invention- 1. The combination, with a swinging bodyundertheinfiuenee of magneiism,of a burner or other source of heatacting to vary the

